For some time the heater on the passenger side of my 99 740iL fails to heat when set normally. By setting that side up around 80+ degrees it blows some heat. Dealer tech looked at it and claimed it worked fine when the wheel between the dash vents was set to red. That was not the fix. Just replaced valley pan, water pump, and all hoses so put in a new auxiliary waterpump, (there was a fault code on that), but I don't expect that to correct problem. I think it is probably a bad heater thermostst on that side. Has anybody encountered this?